Electrical connectors comprise nonconductive housings in which one or more electrically conductive terminals are mounted. The terminals are mechanically and electrically joined to conductive leads, such as Wires, cables or conductive areas on a circuit board. Electrical connectors are employed in mateable pairs, wherein the respective housings and terminals in a pair are mateable With one another. Thus, for example, a pair of electrical connectors may enable electrical connections between the conductors of a cable and the printed circuits on a board.
The mateable terminals in a pair of electrical connectors are specifically designed to achieve substantial contact forces against one another in their fully mated condition. These necessary contact forces can result in significant insertion forces during mating, particularly as the number of terminals in a connector increases.
The existence of high insertion forces creates the possibility that the person Who mates two electrical connectors will stop short of complete insertion. Incomplete insertion of mated connectors typically Will yield less than specified contact forces between the mated terminals and can result in poor electrical performance or unintended separation of the partly mated connectors, particularly in a high vibration environment such as an automobile.
To help ensure complete insertion and to prevent unintended separation of mated connectors, many electrical connector housings are provided with interengageable locks. In particular, one connector may comprise a deflectable latch, while the opposed mateable connector may comprise a locking structure for engagement by the latch. Most prior art connectors with deflectable latches and corresponding locking structures can lockingly retain connectors in their mated condition, but require complex manipulation to achieve mating or unmating. The above described high insertion forces in combination with the manipulation required for the locking means in prior art connectors can make mating and unmating particularly difficult.
The prior art includes ramped locking structures which are intended to assist in the complete insertion of the connectors. In particular, the prior art includes connectors where a deflectable latch on one connector and a corresponding locking structure on the mateable connector are constructed such that the resiliency of the latches and the angular alignment of the ramps cooperate to urge the connectors toward a fully mated condition. Examples of prior art connectors With this general construction are shown in U.S. Pat. No. 4,026,624 which issued to Boag on May 31, 1977 and U.S. Pat. No. 4,273,403 which issued to Cairns on June 16, 1981. In these and other similar prior art connectors, the unmating of connectors is rendered difficult by the need to overcome both the contact forces in the terminals and the ramping forces in the latches of the housing. Thus, although these prior art connectors may facilitate the mating of connectors, they require substantially greater forces for unmating.
The manipulation of these prior art connectors is rendered even more difficult by the complex plural deflections that are required within the latch structures both during mating and during unmating. In particular, prior art connectors of this type have required latch structures that gradually deflect about plural axes during mating and unmating, such as a deflection toward or aWay from the adjacent plane of the connector housing and a deflection parallel to the plane. The excessive forces required for such mating or unmating may be sufficient to damage adjacent parts of the connector, such as the fragile electrical connections between terminals and leads therein. Furthermore, many of the prior art connectors of this type, such as the connectors shown in U.S. Pat. No. 4,026,624, do not provide adequate locking of the connector components in the fully seated condition thereof. Thus, a less than fully mated condition or an accidental unmating is possible.
Prior art latch structures are typically constructed as an integral part of the connector housings, i.e., the housings and latch structures are commonly molded from the same plastic material. However, all plastics will eventually be deformed or yield their shape when submitted to a continuous load. This is particularly true for nylon, which loses its resiliency over time or temperature. Accordingly, prior art latch structures also lose their effectiveness for assisting in the final mating of the connectors.
In view of the above, it is an object of the subject invention to provide a positive latch structure for electrical connectors to ensure complete mating thereof.
It is another object of the subject invention to provide electrical connectors that assist in the final mating thereof and that ensure positively latched engagement in a fully mated condition.
An additional object of the subject invention is to provide electrical connectors that can achieve unmating without the need to overcome ramping forces of deflectable latch components in the housing.
Still another object of the subject invention is to provide electrical connectors where deflectable latches undergo only simple deflection about a single axis during mating and a simple deflection about a different axis during unmating, while still achieving positive locking in the fully mated condition.
A further object of the subject invention is to provide an improved latch structure for electrical connectors which does not lose its resiliency under a continuous load.